Hawthorn

Crataegus monogyna

Efficacy

• Indications with possible efficacy:
  Low Heart failure
• Other indications with no proof of efficacy:
  Angina
  Anxiety
  Arrhythmia
  Atherosclerosis
  Peripheral vascular disease
  Regulation of blood pressure
  Spasms (antispasmodic activity)
  To promote sleep

Security

• Risk of Drug Interactions: High
• Adverse Effects: Not Frequent

Description

Part of the plant used: flower, leaf and berry.

This thorny shrub reaches 2 to 5 meters high, and sometimes up to 7,5 meters. Its medicinal value has been known for centuries but its popularity has really soared in late 19th century in Europe as well as North America. The flowerheads, leaves and fruits were used to treat disturbances of arterial pressure and heart rhythm.

Hawthorn contains flavonoids, cardiotonic amines as well as several other active principles. Its therapeutic value in the treatment of cardiovascular diseases has been extensively studied: hawthorn appears to show strong cardiac activity. It can increase coronary blood flow, the heart's force of contraction as well as cardiac rate, making it useful in the treatment of heart failure. It should however never be used without proper medical monitoring.

Direction of use

• Heart failure :
  The use of standardized oral extracts appear to improve cardiac output, exercise tolerance and symptoms of of NYHA (New York Heart Association) stage I to II congestive heart failure but not to reduce mortality. Treatment must not be started by one-self: a health care provider must be involved.

  Used doses:
  160 to 900 mg of a standardized dry extract of hawthorn leaf with flower extract (2 to 3% flavonoids or 18 to 20% procyanidins) in 2 to 3 divided doses daily.

There is insufficient reliable information to conclude that hawthorn is effective in any other indication.

Precautions

• Side effects
  Hawthorn use has been associated with several, usually mild, adverse effects: nausea, gastrointestinal disturbances, palpitations, sudation, headaches, dizziness and drowsiness.
• Contraindications
  Avoid hawthorn's use if your heart rate or blood pressure is irregular and not well controled. Hawthorn must not be used if heart failure is stages III/IV.
• Interactions
  Hawthorn use may potentiate the effect of digoxin (Lanoxin), requiring a digoxin dose reduction. The use of nitrates, other cardiovascular and antihypertensive drugs may interfere with hawthorn's effects. Before taking hawthorn, check with your pharmacist to make sure that there are no drug interactions with your regular medication.
• Pregnancy and breastfeeding
  Hawthorn is contraindicated in pregnant women because of its potential uterine activity. Since there are no safety data available concerning its use during breast-feeding, lactating women should not use hawthorn.

Warning

In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.

Medicinal plant contents vary naturally from plant to plant - just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.

For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.

References

1. Blumethal M et al. The Complete German Commission E monographs, 1998
2. Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2010
3. Facts and Comparisons, The review of Natural Products, 2000
4. Grainger Bisset, N. Herbal Drugs and Phytopharmaceuticals, 1994
5. Passeportsanté.net. Aubépine. www.passeportsante.net
6. Barnes J. et Al. Herbal Medicines, 2nd edition, Pharmaceutical Press, 2002
7. Herbal Companion to AHFS DI, American Society of Health-System Pharmacists, 2001
8. Taylor J. CE: Phytomedicinals: Uses, precautions, and drug interactions. Drug Topics 2003;1:79
9. Barnes J. et Al. Herbal Interactions, The Pharmaceutical Journal 2003; volume 270
10. Natural Therapeutics Pocket Guide, 2000-2001
11. The Review of Natural Products, 6th Edition, 2010
12. Health Canada, Natural Products Database